diff options
| author | Ian Abbott <abbotti@mev.co.uk> | 2020-10-21 13:21:42 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2020-11-05 11:43:37 +0100 |
| commit | 15506ee68893711b5fb20c76d433fb49928574ea (patch) | |
| tree | 8d3c571e4bfa94b04dae0166b43f672fd620325b /drivers/staging/comedi/drivers/cb_pcidas.c | |
| parent | 4d934fe936fd6c52417d408529b5d45714bea247 (diff) | |
staging: comedi: cb_pcidas: Allow 2-channel commands for AO subdevice
commit 647a6002cb41d358d9ac5de101a8a6dc74748a59 upstream.
The "cb_pcidas" driver supports asynchronous commands on the analog
output (AO) subdevice for those boards that have an AO FIFO. The code
(in `cb_pcidas_ao_check_chanlist()` and `cb_pcidas_ao_cmd()`) to
validate and set up the command supports output to a single channel or
to two channels simultaneously (the boards have two AO channels).
However, the code in `cb_pcidas_auto_attach()` that initializes the
subdevices neglects to initialize the AO subdevice's `len_chanlist`
member, leaving it set to 0, but the Comedi core will "correct" it to 1
if the driver neglected to set it. This limits commands to use a single
channel (either channel 0 or 1), but the limit should be two channels.
Set the AO subdevice's `len_chanlist` member to be the same value as the
`n_chan` member, which will be 2.
Cc: <stable@vger.kernel.org>
Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
Link: https://lore.kernel.org/r/20201021122142.81628-1-abbotti@mev.co.uk
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/staging/comedi/drivers/cb_pcidas.c')
| -rw-r--r-- | drivers/staging/comedi/drivers/cb_pcidas.c | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/drivers/staging/comedi/drivers/cb_pcidas.c b/drivers/staging/comedi/drivers/cb_pcidas.c index 02ae00c95313..1893c70de0b9 100644 --- a/drivers/staging/comedi/drivers/cb_pcidas.c +++ b/drivers/staging/comedi/drivers/cb_pcidas.c @@ -1342,6 +1342,7 @@ static int cb_pcidas_auto_attach(struct comedi_device *dev, if (dev->irq && board->has_ao_fifo) { dev->write_subdev = s; s->subdev_flags |= SDF_CMD_WRITE; + s->len_chanlist = s->n_chan; s->do_cmdtest = cb_pcidas_ao_cmdtest; s->do_cmd = cb_pcidas_ao_cmd; s->cancel = cb_pcidas_ao_cancel; |